And yet on Wednesday (Sept. 18), the Federal Reserve is expected to take its first step toward reducing the extraordinary stimulus it’s supplied to help the U.S. economy rebound from its deepest crisis since the Great Depression.

If it does, the Fed will likely spark a debate: Has the economy strengthened enough to withstand the pullback?

The answer might not be clear for months.

The Fed is meeting this week at a time of deepening uncertainty about who will succeed Chairman Ben Bernanke when his term ends in January. On Sunday, Lawrence Summers, who was considered the leading candidate, withdrew from consideration.

Summers’ withdrawal followed growing resistance from critics. His exit could open the door for his chief rival, Janet Yellen, the Fed’s vice chairwoman. If chosen by President Barack Obama and confirmed by the Senate, Yellen would become the first woman to lead the Fed.